Hideharu was a son of Hatano Harumichi. He recaptured Yakimi castle in 1566 and later sided with Ashikaga Yoshiaki when the latter was estranged with Oda Nobunaga. Hideharu's domain was invaded by the Oda and Hideharu was besieged in Yakimi by Akechi Mitsuhide (1579). He surrendered but was executed, over Mitsuhide's objections, on Nobunaga's orders.
- Initial text from Sengoku Biographical Dictionary (Samurai-Archives.com) FWSeal & CEWest, 2005